用分子模拟方法研究羟基乙叉二膦酸(HEDP)在方解石表面的吸附行为

建立了基于分子力学计算方法的分子模拟手段,用于研究羟基乙叉二膦酸(HEDP)在方解石{104}表面的吸附特性.分子模拟三维吸附图像显示,HEDP中的膦酸基团中的氧原子具有强烈的负电性,能与晶体表面的阳离子产生强烈的静电吸引作用,形成“立体匹配”吸附结构.计算结果显示,HEDP在方解石面上、台阶和扭折点位置的平均吸附能依次约为-5.2eV,-7.0eV和-23.5eV,表明HEDP强烈地吸附到扭折点位置上,从而影响和抑制台阶的生长. 关键词： 分子模拟 方解石 阻垢剂 表面吸附

Molecular dynamics modelling of adsorption of HEDP on calcite surface

The molecular dynamics modeling method is used to study the adsorption characteristics of 1-hydroxyethyldene-1,1-diphosphonic acid(HEDP) on the {104} surface of calcite. The simulated 3-D molecular graphs display that the oxygen atoms in the phosphonate groups of HEDP are strongly electro negative and have high affinity to cationic regions of the surface of the crystals, which results in the inhibitor molecular binding to the crystal surface to form the “multi-site stereo matching". The calculated results show that the adsorption energy of HEDP on the surface, step and kink are -5.2eV,-7.0eV and -23.5eV, respectively. It suggestes that HEDP malecules prefer to adsorb on the kinks to inhibit the development of steps on the calcite surface.